1. Field of the Invention
This invention relates to a tape end detecting device for a tape player which detects a tape end condition in which the tape of a tape cassette is entirely wound on one reel so that the reels are prevented from further rotation, and changes the driving direction of the tape.
2. Background
A conventional tape end detecting device of this type is shown in FIG. 1. Referring thereto. reference numeral 1 denotes reel bases for rotating reels of a tape cassette so as to wind and rewind the tape. A back tension mechanism is contained in the reel base 1. When the tape is entirely wound on one reel, a force applied by the back tension mechanism to angularly move a reel arm 2 is reduced, the reel arm 2 being angularly movable about the axis of the reel base 1.
The two reel arms 1 are connected to a pivotable arm 3, and the arm 3 is pivotably moved in both directions by the angular movements of the reel arms 2. The pivoting movement of the arm 3 causes one sensing arm 4 to angularly move about a pin 5 in the direction of the arrow, with a pawl 4a of the sensing arm disposed in contact with an outer cam of a cam gear 7.
When the force causing the angular movement subsides, the pawl 4a of the sensing arm 4 is engaged with an inner cam of the cam gear 7, and the other end of the sensing arm 4 pushes a switch 6 to operate the same, thereby changing the direction of driving of the tape.
In the above-mentioned tape end detecting device for a tape player, at the time the tape end is encountered, the sensing arm 4 has to be operated by a weak back tension force acting on the reel base 1, and therefore the device must be operated under a very light load.
For this reason, improved surface roughness of holes in the parts as well as dimensional accuracy and precise assembly are required resulting in increased cost of machining and assembly.